3-methyl-4-isopropylphenol-ortho-carboxylic acid useful as an antirheumatic and analgetic



Patented Mar. 17, 1925,

UNITED STATES PATENT oFFIcE WALTER KROPP, 0F ELBERFELD, GERMANY,ASSIGNOR T0 FARBENFABRIKEN VORM.

FRIEDR. BAYER AND 00., 0'15 MANY.

LEVERKUSEN, NEAR COLOGNE- QN-THE-RHINE, GER- No Drawing. Applicationfiled June 3,

To all whom it may concern:

Be it known that I, \VALTER Knorr, a citi-e zen of Germany, residing atElberfeld, in the State of Prussia, Germany, have invented new anduseful Improvements in 3-Methyl- 4-Isopropylphenol-Ortho-Carboxylic'Acid Useful as an Antirheuma-tic and Analgetic, of which the followingis a specification.

The present invention concerns the production of the hitherto unknown3-methyll-isopropylphenol-ortho-carboxylic acid having most probably thefollowing formula:

HOOC

For the roduction of my new compound the 3-met yll-isopropylphenol isconverted into the carboxylic acid according to Kolbes method bytreating it with caustic soda and CO The new product crystallizesfrombenzene in the shape of needles meltin at 189-190 0. Its alcoholicsolution -is co ored blue by ferric chloride. It has proved to be avaluable antirheumatic and analgetic; an average dose being from A; togram. It forms salts with metals e. g. with sodium or calcium. Thesesalts retain the valuable therapeutic properties exhibited by the freeacids.

I In order to illustrate the invention more -fully, the followinexample-is given, the parts being by weig t: i

Dissolve 11 parts of sodium hydroxide 'in 10 parts of water and addthereto by and p by parts of 3-methylbisopropylphenol. The mixture isstirred and heated until it is nearly dry and can be pulverized. The

1924. Serial No. 717,647.

powdered product is then heated during; two hours to 140 0., and at thistemperature a current of dry nitrogen or hydrogen is passed over it. Itis then allowed to cool to 110 and at this temperature a stream of drycarbon dioxide is passed during several hours over the mass which has tobe stirred,

In the course of several hours the temperature is raised to 200 C. andkept at this point. After cooling the resulting product is pulverizedand treated with water and a sodium carbonate solution. It isfilteredand the filtrate is acidulated. The product is redissolved in a sodiumcarbonate solutionand precipitated again.

I The sodium salt of the new acid can be obtained by dissolving it inthe calculated quantity of normal caustic soda solution and evaporation.It is easily soluble in water. I claim p Tho herein described3-methyl-4-isopropylphenol-ortho-carboxylic acid having most probablythe formula: V a

Hooccm I matic and analgetic; forming salts with metals which saltsretain the valuable therapeutic properties of the free acid; the sodiumsalt being easily soluble in water.

In testimony whereof I have hereunto set my hand.

WALTER KROPP.

